The present invention is directed to an arrangement for securing dies to die holders for use as a molding die in an injection molding machine with clamping bolts positioned in the die and extending perpendicularly through an attachment plane provided by contacting surfaces of the die and die holder. The clamping bolts extend perpendicularly to the attachment plane and are arranged in pairs. The bolts project into corresponding holes in the die holder with a device for locking the die to the holder. The locking device includes passageways extending through the die holder from its outside lateral peripheral into the holes for the clamping bolts. Slides extend through the passageways into engagement with the clamping bolts. The slides are wedge-shaped and the clamping bolts have recesses into which the slides fit in locking engagement. Hydraulic piston units, mounted in the passageways, insert the slides into the recesses and hold the slides in the locking or clamping position during operation.
In a known clamping device of this type, disclosed in EP-PS 0 088 100, at least two and preferably four clamping bolts, extending perpendicularly to the contact plane between the die and the die holder, are provided on the rear side of the die for injection molding machines. Each of the clamping bolts has a hole extending transversely through it into which a wedge-shaped slide can be inserted when the clamping bolts are inserted into holes in the die holder. This known attachment arrangement is advantageous to the extent that the molding space between the dies is unencumbered by attachment means for the dies and the die or mold travel can be kept as small as possible with the attachment parts located on the front face of the die holder. There is the disadvantage, however, that the dies can be fastened to the die holder in only two positions turned through 180.degree. around their axes, if the quantity of attachment arrangements at the die holder corresponds to the number of clamping bolts on the rear side of the die.